{[Cu(mal)(bipy)]center dot 2H(2)O}(n): a new one-dimensional ladder-like copper(II) complex based on the mixed N- and O-donor ligands with intrachain ferromagnetic interactions

摘要

The novel ladder-like one-dimensional copper(II) complex of formula {[Cu(mal)(bipy)](.)2H(2)O}(n) (mal, the maleic acid dianion, bipy, 2,2'-bipyridine) has been synthesized using the maleic acid dianion and 2,2'-bipy as the mixed ligands. The single-crystal X-ray diffraction reveals that the two carboxylate groups of the maleic acid dianion exhibit two different coordination modes in the complex. One acts as a bridge in the syn-anti conformation, while the other exhibits the monodentate coordination mode. The magnetic properties of the complex have been studied by susceptibility measurements as a function of the temperature and successfully analyzed in terms of the isotropic spin Hamiltonian for one-dimensional infinite system H = -2JSigmaS(i)S(i+1). Magnetic calculations showed the presence of ferromagnetic exchange interactions between the copper(II) ions within the chain with J = 2.41 cm(-1). (C) 2004 Elsevier B.V. All rights reserved.